An explanation is given by Plutarch in a small work on brotherly love ("Opera Moralia", ed. Reiske, VII, 910). He there tells how the Cretans were often engaged in quarrels among themselves, but became immediately reconciled when an external enemy approached. "And that is their so-called Syncretism." In the sixteenth century the term became known through the "Adagia" of Erasmus, and came into use to designate the coherence of dissenters in spite of their difference of opinions, especially with reference to theological divisions. Later, when the term came to be referred to sygkerannynai, it was inaccurately employed to designate the mixture of dissimilar or incompatible things or ideas. This inexact use continues to some extent even today.

(1) Syncretism is sometimes used to designate the fusion of pagan religions. In the East the intermixture of the civilizations of different nations began at a very early period. When the East was hellenized under Alexander the Great and the Diadochi in the fourth century B. C., the Grecian and Oriental civilizations were brought into contact, and a compromise to a large extent effected. The foreign deities were identified with the native (e. g. Serapis = Zeus, Dionysus) and a fusion of the cults succeeded. After the Romans had conquered the Greeks, the victors, as is known, succumbed to the culture of the vanquished, and the ancient Roman religion became completely hellenized. Later the Romans gradually received all the religions of the peoples whom they subdued, so that Rome became the "temple of the whole world". Syncretism reached its culmination in the third century A. D. under the emperors Caracalla, Heliogabalus, and Alexander Severus (211-35). The countless cults of the Roman Empire were regarded as unessential forms of the same thing- view which doubtless strengthened the tendency towards Monotheism. Heliogabalus even sought to combine Christianity and Judaism with his religion, the cult of the sun-god. Julia Mamæa, the mother of Alexander Severus, attended in Alexandria the lectures of Origen, and Alexander placed in his lararium the images of Abraham and Christ.

(2) A modern tendency in the history of religions sees in the Biblical revealed religion a product of syncretism, the fusion of various religious forms and views. As regards the Old Testament, the Chanaanite myth, the Egyptian, Old Babylonian, and Persian religions are regarded as the sources of Israelitic religion, the latter itself having developed from Fetichism and Animism into Henotheism and Monotheism. It is sought to explain the origin of Christianity from the continuation and development of Jewish ideas and the influx of Brahmanistic, Buddhist, Græco-Roman, and Egyptian religious notions, and from the Stoic and Philonic philosophy; it is held to have received its development and explanation especially. from the neo-Platonic philosophy. That Judaism and Christianity agree with other religions in many of their external forms and ideas, is true ; many religious ideas are common to all mankind. The points of agreement between the Babylonian religions and the Jewish. faith, which provoked a lively discussion some years ago after the appearance of Friedrich Delitzsch's "Babel und Bibel", maybe explained in so far as they exist (e. g.) as due to an original revelation, of which traces, albeit tainted with Polytheism, appear among the Babylonians. In many cases the agreement can be shown to be merely in form, not in content; in others it is doubtful which religion contained the original and which borrowed. As to the special doctrines of the Bible search has been vainly made for sources from which they might have been derived. Catholic theology holds firmly to revelation and to the foundation of Christianity by Jesus of Nazareth.

(3) The Syncretistic Strife is the name given to the theological quarrel provoked by the efforts of Georg Calixt and his supporters to secure a basis on which the Lutherans could make overtures to the Catholic and the Reformed Churches. It lasted from 1640 to 1686. Calixt, a professor in Helmstedt, had through his travels in England, Holland, Italy, and France, through his acquaintance with the different Churches and their representatives, and through his extensiVe study, acquired a more friendly attitude towards the different religious bodies than was then usual among the majority of Lutheran theologians. While the latter firmly adhered to the "pure doctrine", Calixt was not disposed to regard doctrine as the one thing necessary in order to be a Christian, while in doctrine itself he did not regard everything as equally certain and important. Consequently, he advocated unity between those who were in agreement concerning the fundamental minimum, with liberty as to all less fundamental points. In regard to Catholicism, he was prepared (as Melanchthon once was) to concede to the pope a primacy human in origin, and he also admitted that the Mass might be called a sacrifice. On the side of Calixt stood the theological faculties of Helmstedt, Rinteln, and Königsberg; opposed to him were those of Leipzig, Jena, Strasburg, Giessen, Marburg, and Greifswald. His chief opponent was Abraham Calov. The Elector of Saxony was for political reasons an opponent of the Reformed Church, because the other two secular electors (Palatine and Brandenburg) were "reformed", and were getting more and more the advantage of him. In 1649 he sent to the three dukes of Brunswick, who maintained Helmstedt as their common university, a communication in which he voices all the objections of his Lutheran professors, and complains that Calixt wished to extract the elements of truth from all religions, fuse all into an entirely new religion, and so provoke a violent schism. In 1650 Calov was called to Wittenberg as professor, and he signalized his entrance into office with a vehement attack on the Syncretists in Helmstedt. An outburst of polemical writings followed. In 1650 the dukes of Brunswick answered the Elector of Saxony that the discord should not be allowed to increase, and proposed a meeting of the political councillors. Saxony, however, did not favour this suggestion. An attempt to convene a meeting of theologians was not more successful. The theologians of Wittenberg and Leipzig now elaborated a new formula, in which ninety-eight heresies of the Helmstedt theologians were condemned. This formula (consensus) was to be signed by everyone who wished to remain in the Lutheran Church. Outside Wittenberg and Leipzig, however, it was not accepted, and Calixt's death in 1656 was followed by five years of almost undisturbed peace.

The strife was renewed in Hesse-Cassel, where Landgrave Wilhelm VI sought to effect a union between his Lutheran and Reformed subjects, or at least to lessen their mutual hatred. In 1661 he had a colloquy held in Cassel between the Lutheran theologians of the University of Rinteln and the Reformed theologians of the University of Marburg. Enraged at this revival of the Syncretism of Calixt, the Wittenberg theologians in vehement terms called on the Rimteln professors to make their submission, whereupon the latter answered with a detailed defence. Another long series of polemical treatises followed. In Brandenburg-Prussia the Great Elector (Frederick William I) forbade (1663) preachers to speak of the disputes between the Evangelical bodies. A long colloquy in Berlin (Sept., 1662-May, 1663) led only to fresh discord. In 1664 the elector repeated his command that preachers of both parties should abstain from mutual abuse, and should attribute to the other party no doctrine which was not actually held by such party. Whoever refused to sign the form declaring his intention to observe this regulation, was deprived of his position (e. g. Paul Gerhardt, writer of religious songs). This arrangement was later modified, in that the forms were withdrawn, and action was taken only against those who disturbed the peace. The attempts of the Wittenberg theologians to declare Calixt and his school un-Lutheran and heretical were now met by Calixt's son, Friedrich Ulrich Calixt, The latter defended the theology of his father, but also tried to show that his doctrine did not so very much differ from that of his opponents. Wittenberg found its new champion in Ægidius Strauch, who attacked Calixt with all the resources of learning, polemics, sophistry, wit, cynicism, and abuse. The Helmnstedt side was defended by the celebrated scholar and statesman, Hermann Conring. The Saxon princes now recognized the danger that the attempt to carry through the "Consensus" as a formula of belief might lead to a fresh schism in the Lutheran Church, and might thus render its position difficult in the face of the Catholics. The proposals of Calov and his party to continue the refutation and to compel the Brunswick theologians to bind themselves under obligation to the old Lutheran confession, were therefore not carried into effect. On the contrary the Saxon theologians were forbidden to continue the strife in writing. Negotiations for peace then resulted, Duke Ernst the Pious of Saxe-Gotha being especially active towards this end, and the project of establishing a permanent college of theologians to decide theological disputes was entertained. However, the negotiations with the courts of Brunswick, Mecklenburg, Denmark, and Sweden were as fruitless as those with the theological faculties, except that peace was maintained until 1675. Calov then renewed hostilities. Besides Calixt, his attack was now directed particularly against the moderate John Musæus of Jena. Calov succeeded in having the whole University of Jena (and after a long resistance Musæus himself) compelled to renounce Syncretism. But this was his last victory. The elector renewed his prohibition against polemical writings. Calov seemed to give way, since in 1683 he asked whether, in the view of the danger which France then constituted for Germany, a Calixtinic Syncretism with "Papists" and the Reformed were still condemnable, and whether in deference to the Elector of Brandenburg and the dukes of Brunswick, the strife should not be buried by an amnesty, or whether, on the contrary, the war against Syncretism should be continued. He later returned to his attack on the Syncretists, but died in 1686, and with his death the strife ended. The result of the Syncretist Strife was that it lessened religious hatred and promoted mutual forbearance. Catholicism was thus benefited, as it came to be better understood and appreciated by Protestants. In Protestant theology it prepared the way for the sentimental theology of Pietism as the successor of fossilized orthodoxy.